User Manual

Not all of the examinations can be output by ultrasonic low energy ultrasonic can be completed.

Very low energy will only lead to low quality images or weak Doppler signal, thus affecting the

reliability of diagnosis. However, the use of sound power is greater than the actual needs but also

help to improve the quality of information for the diagnosis, but will increase the risk of biological

effects.

Users must be responsible for the safety of patients, to the use of ultrasonic, the output power of

ultrasonic to choose according to the principle of ALARA.

Other information about the ALARA principle and the potential biological effects of ultrasound,

can see the Research Institute of medical ultrasound (AIUM) published the "medical ultrasound

safety" file.

9.4 MI/TI description

9.4.1 Basic knowledge of MI and TI

Ultrasonic output parameters (such as frequency, pressure and intensity etc.) and the relationship

between the biological effect is not yet clear, but acknowledged there are two possible cause

biological effects. One is the thermal effect of ultrasonic absorption, refers to the organization; the

other is a mechanical effect including cavitation effect, thermal index (TI). Said heat effect caused

by temperature index, mechanical index (MI) and MI index.TI index that reflects the mechanical

effect of the instantaneous output, without considering the cumulative effect of the examination

time.

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MI（Mechanical index）：

The mechanical effect is caused by the acoustic wave within the organization micro bubbles,

increasing vibration and the results diabrosis, this reaction is called cavitation.

MI said the possibility of pressure cavitation effect, MI value is obtainedbythesquarerootofthe

peak negative pressure divided by the frequency. Therefore, the higher the frequency or peak

negative pressure is low, the MI value is smaller, so the possibility of generating cavitation effect

is smaller。.

MI =



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